Method of relieving exaggerated uterine contractions



3,437,731 METHOD OF RELIEVING EXAGGERATED UTERlNE CONTRACTIONS Josef Schmitt, LHay-les-Roses, and Marcel Daniel Pierre Brunaud, Paris, France, assignors to Etablissements Clin-Byla, Paris, France, a French company No Drawing. Original application June 22, 1964, Ser. No. 377,070. Divided and this application Feb. 9, 1967, Ser. No. 643,749 Claims priority, applicationgFrance, June 28, 1963,

Int. Cl. A611; 27/00, C07c 93/06, 91/16 US. Cl. 424-330 1 Claim ABSTRACT OF THE DISCLOSURE Method of relieving exaggerated uterine contractions by administering the B forms of N-(Z-phenyl-l-methylethyl) 2-phenoxy-l-methylethylamine.

This application is a division of my copending application, Ser. No. 377,070, filed June 22, 1964.

This invention relates to a secondary amine which is a substituted benzedrine, to the production thereof and to compositions containing the same.

Apart from its intensive peripheral vasodilative properties which give it its therapeutic indications, isoxsuprine of Formula I CH CH3 and acid addition salts thereof. The said amine may be prepared by the reduction, catalytic or otherwise, of the oxime obtainable by the reaction between a benzedrine and phenoxyacetone in stoichiometric proportions. Since benzedrine has an asymmetric carbon atom any form of benzedrine may be used.

The invention also provides a pharmaceutical composition in dosage unit form comprising 2 to 500 rngm. of at least one isomeric form of N-(2-phenyl-l-methylethyl) 2-phenoxy-l-methylethylamine, or an acid addition salt thereof containing a corresponding amount of the amine, together with an excipient.

The compound of the invention has two asymmetric carbon atoms so that there must exist two distinct disastereo-isomeric forms (threo and erythro) each of which, because of the asymmetry of the molecule, can be resolved into optical antipodes. We have therefore synthesised six different substances (four substances which rotate the plane of polarised light and two racemates) since a priori it might be expected that each stereoisomeric form as well as each of the optical isomers would have different physiological activities.

3,437,731 Patented Apr. 8, 1969 To synthesise the various products having the above formula benzedrine and phenoxy acetone can be reacted according to the present invention to produce the imine having the formula This imine is then reduced, for example by a chemical reducing agent of the mixed hydride group, more particularly sodium borohydride or potassium borohydride, or otherwise catalytically, more particularly in the presence of palladium on charcoal.

The intermediate imine which is rather unstable on heating, has not been isolated in the pure state. It can be reduced directly within the reaction mixture as it is formed. The formation of the imine may be carried out in a lower aliphatic alcohol, methanol and ethanol being preferred for this purpose. However, in a modification of the process, to ensure that the imine has been formed quantitatively before reduction, the water forming during the reaction can be entrained by an inert entraining agent, preferably benzene. If the water resulting from the imine formation is not entrained, it is preferable to use a considerable excess of benzedrine to avoid undesirable reduction of some of the phenoxyacetone before condensation. This excess of benzedrine can easily be recovered by fractional distillation of the reduction product and be reused in a subsequent operation.

In every case a mixture is obtained of the two diastereoisomeric forms, the proportions of which will vary with the temperature at which the imine is formed and the method of carrying out the reduction.

The two disastereoisomeric bases can easily and rapidly be distinguished by chromatography on a thin layer of silica using as the solvent mixture: benzene 50, ethyl acetate 50 and absolute ethanol 10 parts by volume and subsequent development by spraying with Dragendorfis reagent. The two diasteroisomeric bases then give stains whose Rf values are respectively in the neighbourhood of 0.59 and 0.51. From the intensity and size of the stains it is possible to obtain a quantitative indication of the composition of the mixture.

For example, catalytic reduction of the imine gives a mixture of substantially equal parts of the two diastereoisomers. On the other hand, reduction of the imine by the borohydride results in a mixture containing approximately 70% of the isomer having an Rf value of 0.59 and 30% of the isomer having an Rf value of 0.51. Finally, formation of the imine in boiling benzene followed by reduction with borohydride gives a mixture of about 60% of the isomer of Rf value 0.59 and 40% of the isomer of Rf value 0.51.

To obtain an adequate rate of reaction the catalytic reduction may be carried out in ethanol at a temperature of about 50 C. under ordinary pressure whilst reduction using a borohydride can be carried out in a lower aliphatic alcohol, especially methanol, at a temperature of between 0 and 30 C.

The preparative separation of the two diastereoisomeric forms may be carried out by fractional crystallisation of their salts. The acid fumarates and the hydrochlorides being particularly suitable for this separation.

Thus, in a mixture of the two forms the acid fumarate of the form having an Rf value of 0.59 crystallises initially because of its lower solubility. The hydrochlorides, on the other hand, behave in the opposite Way. Thus by alternate formation and crystallisation of these two salts the two forms can be isolated in the pure state from a mixture thereof. The form having an Rf value of 0.59 is generally obtained more easily.

If either dor l-benzedrine is used instead of a l-benzedrine, the optical antipodes of the two diastereoisomers are isolated in the same way, their physical properties being very similar to those of the racemic forms, with the anticipated exception of the rotatory power.

Apart from their Rf values in thin-layer chromatography, the two diastereoisomeric forms are also distinguished by their infra-red spectra in the fingerprint region both on the base and on the salts and also by their nuclear magnetic resonance spectra.

The nuclear magnetic resonance spectra were recorded at 60 m./cs. on a Varian A 60 spectrograph, tetramethyl silane being used as internal reference.

Isomer A (Rf 0.51)

Between 6.7 and 7.4 p.p.m. there is a group of peaks due to the aromatic protons.

At about 3.8 ppm. there is a group of two protons attributed to the At about 3 ppm. there is a group of peaks due to two tertiary protons.

At 1.55 p.p.m. there is a peak attributable to the NH group.

Finally, between 0.9 and 1.2 p.p.m. there are two doublets due to the two methyl groups.

Isomer B (Rf 0.59)

The spectrum of the isomer B (Rf 0.59) is very similar to that of the isomer A apart from very slight differences in the shape of the peaks, with the exception of the peak attributable to the NH group which is found at 1.35 ppm. instead of 1.55 ppm.

The absolute configuration of the two forms was not determined exactly. However, there is presumptive evidence that the form having the Rf value 0.59 corresponds to the threo form and that the isomer having the Rf value 0.51 corresponds to the erythro form.

The melting points and rotatory powers are shown in the following table:

4 The ether is evaporated on a water bath under reduced pressure and the residue is distilled in a Claisen flask. After the low boiling products have distilled a yellow liquid is obtained (44 g); boiling point=l-l45 C./ 0.05 mm.

The mixture is distilled a second time in a Claisen flask. There is thus obtained g. of a yellow liquid; boiling point==l32135 C./0.05 mm.

When subjected to thin-layer chromatography the mixture is found to be approximately 30% isomer A (Rf value=0.51) and 70% isomer B (Rf value- 0.59).

Separation of isomer B 38.4 g. of the yellow liquid obtained as described above and 16.5 g. of fumaric acid are dissolved in 275 ml. of boiling absolute alcohol. On cooling a colourless solid separates (38 g); melting point l47l54 C. Recrystallisation of the solid from 9 volumes of absolute alcohol gives 24 g. of fumarate; melting point 162 C.

Thin-layer chromatographic examination on the base liberated from this fumarate indicates that it is the fumarate of the pure isomer B.

Liberation of the base from this fumarafe enables the pure hydrochloride of the isomer B to be prepared therefrom by the action of hydrochloric gas in alcohol; melting p0int=l56l57 C.

Separation of isomer A The mother liquors from the formation and recrystallisation of the fumarate of isomer B are evaporated to dryness. The residue obtained is treated with an alkali to liberate the base therefrom and the latter is extracted with ether. The ether solution is washed with water and then dried over sodium sulphate. The ether is evaporated on a water bath and the base obtained is redistilled. The hydrochloride of this base is formed in alcoholic solution and recrystallised several times from the same solvent until a hydrochloride is obtained having a constant melting point (167l68 C3, melting point of a mixture with the hydrochloride of isomer B: 135-143 C.).

RI Hydrochloride Acid fumarate Melting point, 167168 Melting point, 190191.

Al 0. 51 Melting point, 189490 B dl O. 59 Melting point, 156157.... Melting point, 1

B l 0. 59 Melting point, 186187--..

Melting point, 164-1645- [alu 11.

[11]!) base [0:10 Hydrochloride [(111 Furnarat-e 62 Melting point, 186187 Melting point, lo l-165- Ia]n +41". [a]n +22--- Inflo +19.

(1% ethanol)... (1% ethanol)..... (1% ethanol). la]n =-21.5. [a] =15. (1% ethanol)--. (1% ethanol)-.-- (1% ethanol).

1 All the melting points were determined using a capillary tube and are uncorrected; the degrees are degrees C.

The following examples illustrate the preparation of the new compounds.

EXAMPLE 1 A mixture of 60 g. of dl-benzedrine and 30 g. of phenoxy acetone in 200 ml. of methanol is allowed to remain at room temperature for 3 hours.

The mixture is then cooled in a bath of iced Water and 3.8 g. of sodium borohydride are added with agitation in small quantities so that the temperature of the mixture remains between 10 and 15 C. After the addition the mixture is allowed to stand for 2 hours with agitation at that temperature.

The methanol is evaporated on a water bath under reduced pressure and the residue is taken up in water and ether. The ether layer is separated and is extracted four times with 200 ml. of hydrochloric acid diluted with nine volumes of water. Since the hydrochloride is not very solu- 'ble in water, three layers form. The two lower layers are separated and made alkaline with caustic soda. The liberated base is extracted three times with ether, the solution washed with water, and dried over sodium sulphate.

Thin-layer chromatographic examination of the base liberated from this hydrochloride indicates that it is the hydrochloride of the pure isomer A.

EXAMPLE 2 Separation of isomers (a) Isomer B.The fumarate is formed by dissolving 40 g. of the yellow liquid and 17.2 g. of fumaric acid in ml. of boiling absolute alcohol. A colourless solid slowly separates on cooling. The solid is drained and washed with alcohol; a colourless solid is obtained (28.5 g.) melting at l60l6l C.

Thin-layer chromatographic examination shows that this is the fumarate of the pure isomer B.

A second recrystallisation from alcohol raises the melting point to l64165 C.; [a] =-]-19 (1% in ethanol).

Treatment of this fumarate with alkali in an aqueous solution liberates the base of the pure isomer B; [u] =+4l (1% in ethanol).

From this base it is possible to prepare the hydrochloride of isomer B. The base is dissolved in ether and is treated whilst agitating with an aqueous solution of hydrochloric acid diluted with two volumes of water. A substantially insoluble hydrochloride precipitates. It is drained, washed with a small quantity of water and is then recrystallised from absolute alcohol. A mat of fine bright colourless needles is obtained, melting at l86l87 C.; [cc] =|-22 ethanol).

(b) Isomer A.-The mother liquors from the formation and first recrystallisation of the fumarate of isomer B are evaporated to dryness. The base is liberated by making alkaline with dilute caustic soda and extracting with ether.

The ether solution is washed with water, dried over sodium sulphate and the ether evaporated on a water bath under reduced pressure. The resulting base is distilled. The base is dissolved in ether and the solution is treated with an equimolecular quantity of aqueous hydrochloride acid. The hydrochloride which precipitates is drained and then recrystallised from ethanol. Fine silky colourless needles are obtained which melt at 190191 C. Melting point of mixture with hydrochloride of isomer B: 160-l63 C.; [a] =+22 (1% in ethanol).

The base liberated from this hydrochloride (0.5% in ethanol)] gives a single stain having an Rf value of 0.51 when submitted to thin-layer chromatography.

EXAMPLE 3 The procedure adopted in Example 2 is repeated but the d-benzedrine is replaced by an equal weight of l benzedrine. A yellow oil is obtained (41 g.); boiling point 136-137 C./0.50 mm.

Thin-layer chromatographic examination indicates that this mixture is about 50% of isomer A (Rf value 0.51) and 50% of isomer B (Rf value 0.59).

The isomers are separated as described in Example 2 with the following results:

Isomer B Fumarate melting point: 164-1645 C.,

(1% in ethanol) Hydrochloride melting point: 186-187 C.,

( 1% in ethanol) Base [a] =4l (1% in ethanol) Isomer A Hydrochloride melting point: l89190 C.,

(1% in ethanol) Base [a] =-24 (1% in ethanol).

EXAMPLE 4 In a three-neck flask provided with a mechanical agitator and a water separator there are placed 60 g. of d-benzedrine, 60 g. of phenoxy acetone and 200 ml. of dry benzene. The mixture is heated to reflux with agitation. Water separates rapidly at first and then more and more slowly. In 2.5 hours 6 ml. of water are obtained and the reaction is practically complete. The benzene is eliminated by heating on a water bath unde reduced pressure and then 400 ml. of methanol are added. The

solution is cooled in an ice and salt bath and 10.8 g. of potassium borohydride are then added in small portions whilst agitating so that the temperature remains below +2 C. After completion of the introduction of the borohydride the mixture is allowed to stand whilst agitating for 1.5 hours at room temperature. The methanol is removed by heating on a water bath under reduced pressure and the residue is taken up in water and ether. The ether layer is separated, washed with a small quantity of water and dried over sodium sulphate. The ether is removed by heating upon a water bath and the residue is distilled in a Vigreux flask. After a small quantity of low boiling products have passed over a yellow oil is obtained (84 g.) boiling point 143-145 C./0.1 mm.

Thin-layer chromatographic examination reveals that it is a mixture of approximately 40% of isomer A (Rf value 0.51) and 60% of isomer B (Rf value 0.59). The isomers are separated as described in Example 2.

EXAMPLE 5 The same procedure is followed as that described in Example 4 but on reduction with the potassium borohydride the methanol is replaced by an equal volume of ethanol. The reaction is less rapid and after the introduction of the borohydride the mixture has to be left with agitation at room temperature for 5 hours and is then allowed to stand overnight.

After working up in the same Way as that described in Example 4 a yellow oil is obtained (72.5 g.); boiling point l45 C./0.1 mm.) which when examined by thin-layer chromatography consists of about 40% of isomer A (Rf value 0.51) and 60% of isomer B (Rf value 0.59).

The isomers are separated as described in Example 2.

EXAMPLE 6 30 g. of d-benzedrine and 30 g. of phenoxy acetone are admixed in 300 ml. of ethanol and allowed to stand for 2 hours at ordinary temperature. 3 g. of 5% palladium charcoal are added and the mixture is hydrogenated at 50 C. and ordinary pressure. The absorption is rapid at first and then progressively decreases.

After 4 hours 4865 cc. of hydrogen (theoretically 4480 cc.) has been absorbed and the reaction is practically complete.

After filtration of the catalyst the alcohol is removed by heating on a water bath under reduced pressure and the residue is distilled in a Vigreux flask. After some low boiling materials have passed over a clear yellow oil is obtained (38 g.; boiling point 140145 C./0.05 mm.) which when examined by thin-layer chromatography is found to consist of about 50% of isomer A (Rf value 0.51) and 50% of isomer B (Rf value 0.59).

Separation of the isomers is carried out in the manner described in Example 2.

Comparison of the pharmacological activity of the six isomers of N-(Z-phenyl 1-methyl)-ethyl (2-phenoxy 1- methyl)-ethylamine (hereinafter referred to as 3697 CB) Techniques adopted:

(I) acute toxicity: toxicity was determined in mice subcutaneously for all the isomers and orally for two of the isomers.

Batches of 10 mice weighing about 20 grams originating from one breed were used.

The different isomers were suspended in Water containing 5% of gum, on account of their low solubility at the experimental dosages. The latter varied between 75 and 1000 mg./ kg. body weight. The animals are observed for 48 hours after subcutaneous injection and for 72 hours after oral administration.

(II) Action on uterine motoricity. (A) In vitro: 21 segment of the cornu of the uterus of a rat was suspended in an oxygenated Tyrode bath at 37 C. It was connected to an isotonic myograph recording on a smoke-blackened cylinder. The contractions of the isolated organ are recorded in this Way. Solutions of 3697 CB were added to the bath and the changes that they produced in the amplitude of the movements and their frequency as well as upon the basic tone of the organ were studied.

The doses injected intravenously varied from 0.01 to mg./kg. Changes in the arterial pressure during injection of increasing doses of the different isomers and variations in the hypertensive effects when 0.001 to 0.004 mgJkg. of adrenalin and ncradrenalin injected before and after each dose of 3697 CB were observed.

The action of some of the isomers on the arterial pressure and the rnzdiators were also studied after intraduodenal administration of doses ranging from 0.1 to 50 or 100 mg./kg. of 3697 CB.

(B) In vivo: after anaesthesia and fixation of the rat 10 and after central laparotomy the top part of a uterine Results cornu released cumng It lust below the ovary The Isoxsuprine was used as reference compound for all uterus is held stationary and the end of the cornu 1s fitted these tests. 1n a small chamber and connected to an isotonic myograph. The inside of the chamber is filled with tepid Acute toxicity- Tyrodes solution to maintain the cornu in a tepid and Lethal 10565 g hum d atmosphere. Prior to this, a cannula 1s fitted 1n subcutaneously the ugular vein or 11'] the duodenum to enable solutions of 3697 CB to be administered.

The movements of the uterine cornu are then recorded Isomer: and the changes therein due to the intravenous or intrai gt gig duodenal administration of solutions of 3697 CB are A 83 observed. 1 8 3 (III) Cardiovascular action.The cardiovascular ac- M 228 a tion of the different lsomers of 3697 CB were studied in oxsupn a cat anaesthetised with Nembutal. The arterial pressure (2) Action on uterine motoricity. was recorded by manometer in the peripheral end of the (a) In vitro:uterine cornu of rat suspended in Tyrodes carotid. A cannula was fitted in the jugular vein. solution.

Action on contraction Action on contraction Action on Isomer amplitude frequency basic tone studied (inhibitory Threshold E050 ECm Threshold E05 ECwo threshold cone. cone. (dose) 1-10- 7. 5-10- 1-10-'- 1-10- 1 10- 5-10 7. s10- 7.5-10- 7. 5-10- 110- 6-l0- 2. 5-10- 1-10 2.5-10 1-10- 540- 1-10- 5 2. 5-10- 7.5-10- 7-in- 5-10- 2 5-10- 5 40- 7 5-10- 5-10" 2.5-10 7. 5-10 7.5-10- 1-30- 0. 25-10- 0. 5-10- 140- 1 to 2.5 do 1 10- (b) In vivo:

Method Inhibitory dose (mg.]kg.) in Isomer studied of adminrespect of Observations istration Amplitude Frequency Tone A d ID 20 20 20 1 experiment. Al ID 50 Do. B dl Ills 1-58 :10 6 experiments.

5-5 50 B d --{rv 2 2 5 B l- {R 8 2g {3 experiments.

ID 10 i0 10 Isoxsuprino 1V 0.1-0.2 0.2 0.1 Do.

2 Inhibitory action. 3 Not determined.

4 No action. 6 Substantially unchanged.

(3) Cardiovascular action: (A) venously in anesthetised cat.

. Changes in mediators Isomer Changes in arterial pressure studied and cardiac rhythm Adrenaline Noradrenaline Histamine Acetylcholine Vagal excitability A (ll Transient hypotension after 1 mgJkg. more ac- Reduced Reduced Unchanged.-. Reduced after Reduced after ccntuated after 3. Death at 10. Frequency of 3 mg./kg. 3 mgJkg. heart beat slightly accelerated. A d Transient hypotension from 0.3 to 3 mgjkg. very Reversed alter 1 appreciable and longer lasting after 10 mgJkg. rngJkg. A l Transient hypotension after 1 mgJkg. more ap Slightly reduced preciable after 10 or progressive drop. B d1 Hypotension after 3 mgJkg. followed by pro- Reversed after 10 Also rcverscd Reduced after Unchanged Substantially lggcssivo drop more accentuated after 10 mg.] mgalllrg. or 3 10 mgnlkg. up t/(i unchanged.

g. mg. 'g. mg. g. B d Transient hypotension alter 0.3 to l rug/kg. more Substantially appreciable after 3 to 10. unchanged. B l Drop after 3 or 10 mg./kg., transient in 1 case, Reduced after 3 longer lasting in the other. mgjkg. Re-

versed after 10 a/kg. Isoxsupnnc Drop in arterial pressure from 0.01 to 0.08 mg] Reduced after 0.05 Reduced Unchanged Unchanged Unchanged.

kg. (15-301ninules [or small doses) but several Jug/kg. but

hours [or higher doses (0.1 to 2 rug/kg).

reversed with larger doses.

(B) Intraduodenal administration in anesthetised cat.

Isomer Changes in mediators studied Action on arterial pressure Adrenaline Noradrenaline Histamine Acetylcholine B 6.1 No action up to rngJkg. Appreciable and progressive drop from 50 mgJkg. B d Arterial pressure substantially unchanged Progressively Reduced Reduced after 1 Reduced after reduced. rug/kg. 1 mg. g. B l Substantially unchanged pressure throughout Reduced after Reduced from Reduced from Reduced after 50 mgJkg. 50 mg./kg. 50 mgJkg. 50 mg./kg.

It was also found that 3697 CB had a spasmolytic Mg. action upon the gall bladder and upon the ureter. Thus Rice starch 40 3697 CB, form Bd, had the following actions in vitro: Polyvinylpyrrolidone 20 On isolated guinea pig ureter, 3697 CB (form Bd) 15 Talc 15 reduced the amplitude of contractions at a concentration Magnesium stearate 5 of 1 1O and completely stopped motoricity at a con- Desiccated rice starch centration of 1x10 Silicic acid 5 Oh the Isolated ghhea Pigbladder 3697 CB (form Bd) 20 In connection with the above examples, 3697 CB is completely stopped motoricity and reduced tone at conadvantageously Combined with an analgesic, such as Cehtrahohs. of about 1X10 6 to X 9 codeine, acetyl-para-aminophenol or phenacetin, for the corhpahsoh between the varlohs lsomers of 3697 CB treatment of dysmenorrhoea, whilst codeine reinforces Whh lsoxshpnhe used as reference compound Shows the action of 3697 CB against uterine contractions.

a i r In the foregoin example of com ositions 3697 CB lsomehs of the grohp B of 3697 CB are the most 2 is stated to be pres nt in the form of the fumarate thereof achvc h htehhe relaxlhg aghhtsi but generally it may be present in the form of one of the (h) hsomers B are less toxlc than lsoxshpnhe; acid addition salts thereof derived from pharmaceutically lsomers are hhdohhtedly less .achve than 150x" acceptable acids such as inorganic acids, for example hy- Shpnhe h htenhe relaxlhg hgehtsnhhhslhce less drochloric acid, sulphuric acid, phosphoric acid and the hypotensive their therapeutic use in disorders dependent like, or Organic acids for example acetic acid, formic hpoh heahheht by uterus relaxmg agents can he favour acid, succinic acid, maleic acid, fumaric acid, lacetic acid, ably cohsldered' ascorbic acid, citric acid, glutonic acid, aminoacetic acid,

Amhhgst these Homers B Preferehce 1S glveh to the glutamic acid, levulinic acid and the like, or complex ormcemlc form hh h dextmmiatory form ganic acids such as tannic acid, embonic acid, pectins therahehhc lhdlchhohs reshlhhg th p h and pectic acids and the derivatives thereof, polyacrylic cological activity of the product are conditions in which acids (carbopoles) resins having an acid character and exaggerated uterine cohtracthohs to combated like compounds capable of yielding with basic amino dysmchorrhqeh and the risk of hhscamage; 3697 CB compounds sparingly soluble salts which liberate the accah also be used In the treatment of spasms of the ureter 40 tive substance slowly at the site of intestinal mucous memahd of the.gah h brane so as to protract the activity thereof.

The dahy qhahhty of compound be admmhstered Tablets incorporating the herein described substituted may be from 2 to 500 of base (Preferably 1h salt benzedrines may be produced according to conventional form) double compression or granulation techniques, using a The compounds according to the invention can be comgum aqueous solution or a non-aqueous solvent such as hh Whh ah exclpleht h i ahmlhlstrahoh. 9 an ethyl alcohol. Suitable carriers include for example starch, cipient for parenteral administration for medicinal use. talcum, gunrarabic magnesium stearate, carboxymethyl 10 vllisxarnples of pharmaceutical compositio s are as cellulose and the like. The tablets may be made enteric for example by roviding them with a gluten coating or a (1) Tablets were made each of whlch cohtalhed coating with ano ther substance unaffected by gastric juice Mg. such as cellulose acetophthalate, with a view to prevent- 3697 CB B racemate (dl) (in form of fumarate, ing the active substance to be attacked by gastric hydroi.e., 107.31 mg. of fumarate) 75 chloric acid or again with a view to avoiding possible Codeine phosphate 9.60 stomarch troubles. The tablets may also be given a sugar Acetylpararninophenol 250 or other Outer coating, which may be opaque and may be Ethyl cellulose N 50 l0 coloured if desired.

Desiccated rice starch 30 What we claim is:

Polyvinylpyrrolidone 30 1. The method of relieving exaggerated uterine con- Ultra-amylopectin N 30 tractions in female patients exhibiting exaggerated uterine Talc 83.09 50 contractions which comprises the step of administering to Silicic acid 5 said patient a therapeutically administrable form of the Parafiin oil 15 B isomeric forms of N-(2-phenyl-1-methylethyl) 2-phenoxy-l-methylethrylamine in an amount sufiicient to sup- (2) Ampoules were made each containing ply 2 to 500 mgm. of said amine per day.

3697 CB B dextrorotatory (d) mg 50 Lactic acid mg 20 References Cited Sodium hydroxide quantity SllffiCifillt 110 UNITED STATES PATENTS produce pH=5 Distilled water quantity sufiicient for ml 1 3056836 10/1962 Moed 260-570] (3) Tablets were made each of which contained ALBERT T. MYERS, Primary Examiner.

Mg, S. J. FRIEDMAN, Assistant Examiner. 3697 CB B racemate (in form of fumarate, i.e., I

107.31 mg. of fumarate) Lactose 62.69 75 260-501, 566, 570.6, 570.5, 570.7 

